TGF-β and IL-1β regulate Et-1–induced IL-8 production. CNS-EC cultures were left untreated or treated with Et-1 (10⁻⁷ mol/L), TGF-β (10 ng/mL), or IL-1β (1 pg/mL) separately or in the combinations of TGF-β + Et-1 or IL-β + Et-1. After 72 hours of culture, the supernatants were analyzed for IL-8 production using the ELISA. Results are the mean ± SEM of triplicate cultures. This represents one of three experiments performed.